Heating and cooling apparatus



Aug. 20, 1957 F. FIKENSCHER HEATING AND COOLING APPARATUS Filed Sept. 25, 1953 H EATED O AIR GAS I6 I l5 l9 SUPER HEATED STEAM 7 L A 9 L s a 1 1M FEED WATER COOL 5 '6 COOLED GAS ilnited rates Patent I-EATING AND COOLHQG APPARATUS Friedrich Fikenscher, Gnmmers'nach, Rhineland, Germany, assignor to L. & C. Steinmuller G. m. b. H., Gummersbaeh, Rhineland, Germany Application September 25, 1953, Serial No. 332,410

Claims priority, application Germany ()ctober 7, 1952 2 Claims. (Cl. 257-6) The invention relates to an air preheater divided into stages, more particularly for steam boilers.

It has already been proposed to divide up the rotating member of recuperative air preheaters into two or more partial rotors which are separately secured on the same shaft, there being additionally provided, for example, in the flue-gas passages arranged in the connecting casing between the partial rotors, cooling surfaces which are traversed by another cooling medium. The said additional cooling surfaces have already been constructed as feed-water heaters or parts thereof associated with the boiler plant.

The invention consists in this that in such an air preheater, more particularly when it is constructed as a rotating recuperative air preheater, heat exchangers are additionally installed on the air side between the various stages of air preheaters. The temperature in the said heat exchangers can be controlled as desired and within wide limits by suitably arranging and dimensioning both the groups of air preheaters and the heat exchangers installed therebetween.

The heat exchangers are rigidly installed and can be employed with various media. In certain temperature conditions they can also be wholly or partially arranged in the direction of the air flow behind the whole air preheater.

The invention has particular advantages when employed in connection with rotat ng recuperative air preheaters, since in air preheaters of this type the gas and air passages can be arranged in a very simple manner.

A constructional example of the invention is shown in the single figure of the accompanying drawing.

Other and further objects, features and advantages of the invention will be pointed out hereinafter and appear in the appended claims forming part of the application.

In the accompanying drawings, a preferred form of the invention is shown by way of illustration and not by way of limitation.

The single figure in the drawing is an elevation, partly in section, showing an embodiment of a Ljungstrom rotary, regenerative air preheater.

Referring in particular to the drawing, numeral 15 designates the housing of a rotary regenerative air preheater having two cylindrical rotor elements 1 and 2 fixedly mounted on a shaft 16 and spaced from each other so as to define between the rotors a fine gas compartment 17 and an air compartment 18 for the purpose which will be hereinafter explained. Each rotor element is divided by radial partitions (not shown) into sector shaped compartments. Each compartment of the rotor contains regenerative heat transfer surfaces 19 which first absorb heat from line gases in passing through the gas side of the preheater and then impart it to air passing through the ice air side of the preheater as the rotor is turned slowly about its axis by a motor 20 operating on the shaft 16 through a suitable reduction gearing. The flue gases are introduced into the housing 15 through an inlet duct 3 and discharged through an outlet duct 5 while the air to be preheated is blown into the housing 15 through the exhaust branch 6' of an air blower or fan 6 and conveyed to the furnace or other place of use through an outlet branch 8.

Fixedly mounted in the compartments 17 and 18 between the rotor elements 1 and 2 are heat exchangers in the form of coils 4 and 7. The heat exchanger 4 serves to act as a cooling surface for the flue gas passing through the compartment 17 and may be traversed by the water or steam of a boiler or by the feed water of a boiler, for preheating same after the manner of an economizer.

The heat exchanger 7 may preferably be traversed by superheated steam which thus is desuperheated while at the same time heating the air.

The inlet and outlet branches of the coil 7 can be shortcircuited through a by-pass valve 9.

It will thus be understood that the final temperature of the flue gas leaving the air preheater at 5 and the final temperature of the air leaving the air preheater at 8 can be influenced within wide limits by suitable dimensioning of the heat exchangers 4 and 7 and by suitable adjustment of the flow of the medium passing through the coils 4 and 7, as by valve 9.

It will be appreciated that the structure shown will result in many possibilities for regulating the temperature both of the medium flowing through the heat exchanger and of the air.

I claim:

1. In regenerative heat exchange apparatus, a housing, means defining passages for a heating gas and air through said housing, ducts for supplying hot gas and relatively cool air to and for withdrawing the cooled gas and heated air from said passages, a plurality of coaxial vertically spaced rotors within the housing, each rotor being divided into a plurality of compartments containing regenerative material adapted to be moved first through the gas passage to absorb heat from the gas and then into the air passage to impart the heat to the air, means in the gas passage in the space between the rotors for reducing the temperature of the gas passing through such space, and means in the air passage in the space between the rotors for heating the air passing through such space.

2. A regenerative heat exchange apparatus as set forth in claim 1 wherein the means in the space between the rotors in the gas passage and the means in the space between the rotors in the air passage is each a coil, means connecting the coil in the gas passage to a source of feed water, means connecting the coil in the air passage to a source of superheated steam and valve means controlling the flow into the coil in the air passage.

References Cited in the file of this patent UNITED STATES PATENTS 2,321,129 Cooper June 8, 1943 2,363,870 Karlsson et al Nov. 28, 1944 2,594,471 Marshall Apr. 29, 1952 2,673,718 Ljungstrom Mar. 30, 1954 FOREIGN PATENTS 447,208 Italy Apr. 6, 1949 575,509 Great Britain Feb. 21, 1946 

